The present invention is related to control assemblies for operating agricultural tractors provided with a power-shift electronically controlled transmission with a reversing gear and associated first control members for the gear ratio shifting and second control members for selecting forward and reverse speed, as well as with an electronic control device for the engine rotation speed with associated third control members.
Traditionally the above control members for operating an agricultural tractor are arranged in different areas within the driver's cab or, according to more recent solutions, they are grouped in a control handle, which may possibly perform additional functions. In both cases operation of the control members by the driver can be sometimes uncomfortable and inconvenient.
It is known, in the field of bulldozers and earthworking vehicles, to have a control console arranged on one side of the vehicle operator's seat. For instance, patent U.S. Pat. No. 4,646,869 discloses a console with projecting control levers and patent U.S. Pat. No. 5,244,066 shows a control console with control levers and a rotary knob extending from the front end of an operator's seat handrest. These arrangements employ mechanical linkages housed within the console, thus involving problems of encumbrance and a bulky construction. Moreover, operation thereof may be uncomfortable and fatiguing.
Similar arrangements, specifically applied to tractors, are also disclosed in patents U.S. Pat. No. 4,055,230 and U.S. Pat. No. 5,086,869 as well, in connection with a fork lift truck, in FR-A-2.388.692.
Also known are, in the field of omnibus and cars and even aircrafts, switch control units for operating auxiliary electrical equipment, which are carried by a vehicle seat armrest, as in the case of European patent application EP-A-0537718 and patent U.S. Pat. No. 4,416,488.